// -*- mode: java; c-basic-offset: 2; -*-
// Copyright (C) 2001,2005-2011 by Jarno Elonen <elonen@iki.fi>
// and Copyright (C) 2010 by Konstantinos Togias <info@ktogias.gr>
// See Details at end of file.
package com.google.appinventor.components.runtime.util;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URLEncoder;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.Date;
import java.util.Enumeration;
import java.util.Vector;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.TimeZone;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;

import android.util.Log;

/**
 * A simple, tiny, nicely embeddable HTTP 1.0 (partially 1.1) server in Java
 *
 * <p> NanoHTTPD version 1.25,
 * Copyright &copy; 2001,2005-2012 Jarno Elonen (elonen@iki.fi, http://iki.fi/elonen/)
 * and Copyright &copy; 2010 Konstantinos Togias (info@ktogias.gr, http://ktogias.gr)
 *
 * Improvements in Thread Handling (pooling) by Jeffrey I. Schiller (jis@mit.edu)
 *
 * <p><b>Features + limitations: </b><ul>
 *
 *    <li> Only one Java file </li>
 *    <li> Java 1.1 compatible </li>
 *    <li> Released as open source, Modified BSD licence </li>
 *    <li> No fixed config files, logging, authorization etc. (Implement yourself if you need them.) </li>
 *    <li> Supports parameter parsing of GET and POST methods (+ rudimentary PUT support in 1.25) </li>
 *    <li> Supports both dynamic content and file serving </li>
 *    <li> Supports file upload (since version 1.2, 2010) </li>
 *    <li> Supports partial content (streaming)</li>
 *    <li> Supports ETags</li>
 *    <li> Never caches anything </li>
 *    <li> Doesn't limit bandwidth, request time or simultaneous connections </li>
 *    <li> Default code serves files and shows all HTTP parameters and headers</li>
 *    <li> File server supports directory listing, index.html and index.htm</li>
 *    <li> File server supports partial content (streaming)</li>
 *    <li> File server supports ETags</li>
 *    <li> File server does the 301 redirection trick for directories without '/'</li>
 *    <li> File server supports simple skipping for files (continue download) </li>
 *    <li> File server serves also very long files without memory overhead </li>
 *    <li> Contains a built-in list of most common mime types </li>
 *    <li> All header names are converted lowercase so they don't vary between browsers/clients </li>
 *
 * </ul>
 *
 * <p><b>Ways to use: </b><ul>
 *
 *    <li> Run as a standalone app, serves files and shows requests</li>
 *    <li> Subclass serve() and embed to your own program </li>
 *    <li> Call serveFile() from serve() with your own base directory </li>
 *
 * </ul>
 *
 * See the end of the source file for distribution license
 * (Modified BSD licence)
 */
public class NanoHTTPD
{
  private static final String LOG_TAG = "AppInvHTTPD"; // using this tag on purpose
                                                       // when filtering logcat for
                                                       // interesting message, will
                                                       // use this tag to search

        // ==================================================
        // API parts
        // ==================================================

        /**
         * Override this to customize the server.<p>
         *
         * (By default, this delegates to serveFile() and allows directory listing.)
         *
         * @param uri   Percent-decoded URI without parameters, for example "/index.cgi"
         * @param method        "GET", "POST" etc.
         * @param parms Parsed, percent decoded parameters from URI and, in case of POST, data.
         * @param header        Header entries, percent decoded
         * @return HTTP response, see class Response for details
         */
        public Response serve( String uri, String method, Properties header, Properties parms, Properties files, Socket mySocket )
        {
                myOut.println( method + " '" + uri + "' " );

                Enumeration e = header.propertyNames();
                while ( e.hasMoreElements())
                {
                        String value = (String)e.nextElement();
                        myOut.println( "  HDR: '" + value + "' = '" +
                                                                header.getProperty( value ) + "'" );
                }
                e = parms.propertyNames();
                while ( e.hasMoreElements())
                {
                        String value = (String)e.nextElement();
                        myOut.println( "  PRM: '" + value + "' = '" +
                                                                parms.getProperty( value ) + "'" );
                }
                e = files.propertyNames();
                while ( e.hasMoreElements())
                {
                        String value = (String)e.nextElement();
                        myOut.println( "  UPLOADED: '" + value + "' = '" +
                                                                files.getProperty( value ) + "'" );
                }

                return serveFile( uri, header, myRootDir, true );
        }

        /**
         * HTTP response.
         * Return one of these from serve().
         */
        public class Response
        {
                /**
                 * Default constructor: response = HTTP_OK, data = mime = 'null'
                 */
                public Response()
                {
                        this.status = HTTP_OK;
                }

                /**
                 * Basic constructor.
                 */
                public Response( String status, String mimeType, InputStream data )
                {
                        this.status = status;
                        this.mimeType = mimeType;
                        this.data = data;
                }

                /**
                 * Convenience method that makes an InputStream out of
                 * given text.
                 */
                public Response( String status, String mimeType, String txt )
                {
                        this.status = status;
                        this.mimeType = mimeType;
                        try
                        {
                                this.data = new ByteArrayInputStream( txt.getBytes("UTF-8"));
                        }
                        catch ( java.io.UnsupportedEncodingException uee )
                        {
                                uee.printStackTrace();
                        }
                }

                /**
                 * Adds given line to the header.
                 */
                public void addHeader( String name, String value )
                {
                        header.put( name, value );
                }

                /**
                 * HTTP status code after processing, e.g. "200 OK", HTTP_OK
                 */
                public String status;

                /**
                 * MIME type of content, e.g. "text/html"
                 */
                public String mimeType;

                /**
                 * Data of the response, may be null.
                 */
                public InputStream data;

                /**
                 * Headers for the HTTP response. Use addHeader()
                 * to add lines.
                 */
                public Properties header = new Properties();
        }

        /**
         * Some HTTP response status codes
         */
        public static final String
                HTTP_OK = "200 OK",
                HTTP_PARTIALCONTENT = "206 Partial Content",
                HTTP_RANGE_NOT_SATISFIABLE = "416 Requested Range Not Satisfiable",
                HTTP_REDIRECT = "301 Moved Permanently",
                HTTP_NOTMODIFIED = "304 Not Modified",
                HTTP_FORBIDDEN = "403 Forbidden",
                HTTP_NOTFOUND = "404 Not Found",
                HTTP_BADREQUEST = "400 Bad Request",
                HTTP_INTERNALERROR = "500 Internal Server Error",
                HTTP_NOTIMPLEMENTED = "501 Not Implemented";

        /**
         * Common mime types for dynamic content
         */
        public static final String
                MIME_PLAINTEXT = "text/plain",
                MIME_HTML = "text/html",
                MIME_DEFAULT_BINARY = "application/octet-stream",
                MIME_XML = "text/xml";

        // ==================================================
        // Socket & server code
        // ==================================================

        private static final int REPL_STACK_SIZE = 256*1024;

        /**
         * Starts a HTTP server to given port.<p>
         * Throws an IOException if the socket is already in use
         */

        public NanoHTTPD( int port, File wwwroot ) throws IOException
        {
                myTcpPort = port;
                this.myRootDir = wwwroot;
                myServerSocket = new ServerSocket( myTcpPort );
                myThread = new Thread(new Runnable()
                        {
                                public void run()
                                {
                                        try
                                        {
                                                while( true )
                                                        new HTTPSession( myServerSocket.accept());
                                        }
                                        catch ( IOException ioe )
                                        {}
                                }
                  });
                myThread.setDaemon( true );
                myThread.start();
        }

        /**
         * Stops the server.
         */
        public void stop()
        {
                try
                {
                        myServerSocket.close();
                        myThread.join();
                }
                catch ( IOException ioe ) {}
                catch ( InterruptedException e ) {}
        }


        /**
         * Starts as a standalone file server and waits for Enter.
         */
        public static void main( String[] args )
        {
                myOut.println( "NanoHTTPD 1.25 (C) 2001,2005-2011 Jarno Elonen and (C) 2010 Konstantinos Togias\n" +
                                "(Command line options: [-p port] [-d root-dir] [--licence])\n" );

                // Defaults
                int port = 80;
                File wwwroot = new File(".").getAbsoluteFile();

                // Show licence if requested
                for ( int i=0; i<args.length; ++i )
                if(args[i].equalsIgnoreCase("-p"))
                        port = Integer.parseInt( args[i+1] );
                else if(args[i].equalsIgnoreCase("-d"))
                        wwwroot = new File( args[i+1] ).getAbsoluteFile();
                else if ( args[i].toLowerCase().endsWith( "licence" ))
                {
                        myOut.println( LICENCE + "\n" );
                        break;
                }

                try
                {
                        new NanoHTTPD( port, wwwroot );
                }
                catch( IOException ioe )
                {
                        myErr.println( "Couldn't start server:\n" + ioe );
                        System.exit( -1 );
                }

                myOut.println( "Now serving files in port " + port + " from \"" + wwwroot + "\"" );
                myOut.println( "Hit Enter to stop.\n" );

                try { System.in.read(); } catch( Throwable t ) {}
        }

        private class myThreadFactory implements ThreadFactory {

          public Thread newThread(Runnable r) {
            Thread retval = new Thread(new ThreadGroup("biggerstack"), r, "HTTPD Session", REPL_STACK_SIZE);
            retval.setDaemon(true);
            return retval;
          }
        }

        /**
         * Our Thread Pool Executor which manages a pool of threads for handling requests.
         * We start with 2 threads (one for handling _newblocks calls and one for the long
         * running _values call. Max of 10 (in case of a spike of some kind, should really never
         * have more then 2 or 3). Shutdown any execess idle threads (above 2) after 5 seconds.
         */

        private ThreadPoolExecutor myExecutor = new ThreadPoolExecutor(2, 10, 5,
          TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new myThreadFactory());

        /**
         * Handles one session, i.e. parses the HTTP request
         * and returns the response.
         */
        private class HTTPSession implements Runnable
        {
                public HTTPSession( Socket s )
                {
                        mySocket = s;
                        Log.d(LOG_TAG, "NanoHTTPD: getPoolSize() = " + myExecutor.getPoolSize());
                        myExecutor.execute(this);
                }

                public void run()
                {
                        try
                        {
                                InputStream is = mySocket.getInputStream();
                                if ( is == null) return;

                                // Read the first 8192 bytes.
                                // The full header should fit in here.
                                // Apache's default header limit is 8KB.
                                int bufsize = 8192;
                                byte[] buf = new byte[bufsize];
                                int rlen = is.read(buf, 0, bufsize);
                                if (rlen <= 0) return;

                                // Create a BufferedReader for parsing the header.
                                ByteArrayInputStream hbis = new ByteArrayInputStream(buf, 0, rlen);
                                BufferedReader hin = new BufferedReader( new InputStreamReader( hbis ));
                                Properties pre = new Properties();
                                Properties parms = new Properties();
                                Properties header = new Properties();
                                Properties files = new Properties();

                                // Decode the header into parms and header java properties
                                decodeHeader(hin, pre, parms, header);
                                String method = pre.getProperty("method");
                                String uri = pre.getProperty("uri");

                                long size = 0x7FFFFFFFFFFFFFFFl;
                                String contentLength = header.getProperty("content-length");
                                if (contentLength != null)
                                {
                                        try { size = Integer.parseInt(contentLength); }
                                        catch (NumberFormatException ex) {}
                                }

                                // We are looking for the byte separating header from body.
                                // It must be the last byte of the first two sequential new lines.
                                int splitbyte = 0;
                                boolean sbfound = false;
                                while (splitbyte < rlen)
                                {
                                        if (buf[splitbyte] == '\r' && buf[++splitbyte] == '\n' && buf[++splitbyte] == '\r' && buf[++splitbyte] == '\n') {
                                                sbfound = true;
                                                break;
                                        }
                                        splitbyte++;
                                }
                                splitbyte++;

                                // Write the part of body already read to ByteArrayOutputStream f
                                OutputStream f;
                                if ( method.equalsIgnoreCase( "PUT" ) )
                                {
                                        File tmpfile = File.createTempFile("upload", "bin");
                                        tmpfile.deleteOnExit();
                                        f = new FileOutputStream(tmpfile);
                                        files.put("content", tmpfile.getAbsolutePath());
                                }
                                else
                                {
                                        f = new ByteArrayOutputStream();
                                }
                                if (splitbyte < rlen) f.write(buf, splitbyte, rlen-splitbyte);

                                // While Firefox sends on the first read all the data fitting
                                // our buffer, Chrome and Opera sends only the headers even if
                                // there is data for the body. So we do some magic here to find
                                // out whether we have already consumed part of body, if we
                                // have reached the end of the data to be sent or we should
                                // expect the first byte of the body at the next read.
                                if (splitbyte < rlen)
                                        size -= rlen - splitbyte +1;
                                else if (!sbfound || size == 0x7FFFFFFFFFFFFFFFl)
                                        size = 0;

                                // Now read all the body and write it to f
                                buf = new byte[512];
                                while ( rlen >= 0 && size > 0 )
                                {
                                        rlen = is.read(buf, 0, 512);
                                        size -= rlen;
                                        if (rlen > 0)
                                                f.write(buf, 0, rlen);
                                }

                                // If the method is POST, there may be parameters
                                // in data section, too, read it:
                                if ( method.equalsIgnoreCase( "POST" ))
                                {
                                        // Get the raw body as a byte []
                                        byte [] fbuf = ((ByteArrayOutputStream)f).toByteArray();

                                        // Create a BufferedReader for easily reading it as string.
                                        ByteArrayInputStream bin = new ByteArrayInputStream(fbuf);
                                        BufferedReader in = new BufferedReader( new InputStreamReader(bin));

                                        String contentType = "";
                                        String contentTypeHeader = header.getProperty("content-type");
                                        StringTokenizer st = new StringTokenizer( contentTypeHeader , "; " );
                                        if ( st.hasMoreTokens()) {
                                                contentType = st.nextToken();
                                        }

                                        if (contentType.equalsIgnoreCase("multipart/form-data"))
                                        {
                                                // Handle multipart/form-data
                                                if ( !st.hasMoreTokens())
                                                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but boundary missing. Usage: GET /example/file.html" );
                                                String boundaryExp = st.nextToken();
                                                st = new StringTokenizer( boundaryExp , "=" );
                                                if (st.countTokens() != 2)
                                                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but boundary syntax error. Usage: GET /example/file.html" );
                                                st.nextToken();
                                                String boundary = st.nextToken();

                                                decodeMultipartData(boundary, fbuf, in, parms, files);
                                        }
                                        else
                                        {
                                                // Handle application/x-www-form-urlencoded
                                                String postLine = "";
                                                char pbuf[] = new char[512];
                                                int read = in.read(pbuf);
                                                while ( read >= 0 && !postLine.endsWith("\r\n") )
                                                {
                                                        postLine += String.valueOf(pbuf, 0, read);
                                                        read = in.read(pbuf);
                                                }
                                                postLine = postLine.trim();
                                                decodeParms( postLine, parms );
                                        }
                                        in.close();
                                }
                                else if ( method.equalsIgnoreCase( "PUT " ) )
                                {
                                        f.close();  // Close open file
                                }

                                // Ok, now do the serve()
                                Response r = serve( uri, method, header, parms, files, mySocket );
                                if ( r == null )
                                        sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: Serve() returned a null response." );
                                else
                                        sendResponse( r.status, r.mimeType, r.header, r.data );

                                is.close();
                        }
                        catch ( IOException ioe )
                        {
                                try
                                {
                                        sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
                                }
                                catch ( Throwable t ) {}
                        }
                        catch ( InterruptedException ie )
                        {
                                // Thrown by sendError, ignore and exit the thread.
                        }
                }

                /**
                 * Decodes the sent headers and loads the data into
                 * java Properties' key - value pairs
                **/
                private  void decodeHeader(BufferedReader in, Properties pre, Properties parms, Properties header)
                        throws InterruptedException
                {
                        try {
                                // Read the request line
                                String inLine = in.readLine();
                                if (inLine == null) return;
                                StringTokenizer st = new StringTokenizer( inLine );
                                if ( !st.hasMoreTokens())
                                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Syntax error. Usage: GET /example/file.html" );

                                String method = st.nextToken();
                                pre.put("method", method);

                                if ( !st.hasMoreTokens())
                                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Missing URI. Usage: GET /example/file.html" );

                                String uri = st.nextToken();

                                // Decode parameters from the URI
                                int qmi = uri.indexOf( '?' );
                                if ( qmi >= 0 )
                                {
                                        decodeParms( uri.substring( qmi+1 ), parms );
                                        uri = decodePercent( uri.substring( 0, qmi ));
                                }
                                else uri = decodePercent(uri);

                                // If there's another token, it's protocol version,
                                // followed by HTTP headers. Ignore version but parse headers.
                                // NOTE: this now forces header names lowercase since they are
                                // case insensitive and vary by client.
                                if ( st.hasMoreTokens())
                                {
                                        String line = in.readLine();
                                        while ( line != null && line.trim().length() > 0 )
                                        {
                                                int p = line.indexOf( ':' );
                                                if ( p >= 0 )
                                                        header.put( line.substring(0,p).trim().toLowerCase(), line.substring(p+1).trim());
                                                line = in.readLine();
                                        }
                                }

                                pre.put("uri", uri);
                        }
                        catch ( IOException ioe )
                        {
                                sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
                        }
                }

                /**
                 * Decodes the Multipart Body data and put it
                 * into java Properties' key - value pairs.
                **/
                private void decodeMultipartData(String boundary, byte[] fbuf, BufferedReader in, Properties parms, Properties files)
                        throws InterruptedException
                {
                        try
                        {
                                int[] bpositions = getBoundaryPositions(fbuf,boundary.getBytes());
                                int boundarycount = 1;
                                String mpline = in.readLine();
                                while ( mpline != null )
                                {
                                        if (mpline.indexOf(boundary) == -1)
                                                sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but next chunk does not start with boundary. Usage: GET /example/file.html" );
                                        boundarycount++;
                                        Properties item = new Properties();
                                        mpline = in.readLine();
                                        while (mpline != null && mpline.trim().length() > 0)
                                        {
                                                int p = mpline.indexOf( ':' );
                                                if (p != -1)
                                                        item.put( mpline.substring(0,p).trim().toLowerCase(), mpline.substring(p+1).trim());
                                                mpline = in.readLine();
                                        }
                                        if (mpline != null)
                                        {
                                                String contentDisposition = item.getProperty("content-disposition");
                                                if (contentDisposition == null)
                                                {
                                                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but no content-disposition info found. Usage: GET /example/file.html" );
                                                }
                                                StringTokenizer st = new StringTokenizer( contentDisposition , "; " );
                                                Properties disposition = new Properties();
                                                while ( st.hasMoreTokens())
                                                {
                                                        String token = st.nextToken();
                                                        int p = token.indexOf( '=' );
                                                        if (p!=-1)
                                                                disposition.put( token.substring(0,p).trim().toLowerCase(), token.substring(p+1).trim());
                                                }
                                                String pname = disposition.getProperty("name");
                                                pname = pname.substring(1,pname.length()-1);

                                                String value = "";
                                                if (item.getProperty("content-type") == null) {
                                                        while (mpline != null && mpline.indexOf(boundary) == -1)
                                                        {
                                                                mpline = in.readLine();
                                                                if ( mpline != null)
                                                                {
                                                                        int d = mpline.indexOf(boundary);
                                                                        if (d == -1)
                                                                                value+=mpline;
                                                                        else
                                                                                value+=mpline.substring(0,d-2);
                                                                }
                                                        }
                                                }
                                                else
                                                {
                                                        if (boundarycount> bpositions.length)
                                                                sendError( HTTP_INTERNALERROR, "Error processing request" );
                                                        int offset = stripMultipartHeaders(fbuf, bpositions[boundarycount-2]);
                                                        String path = saveTmpFile(fbuf, offset, bpositions[boundarycount-1]-offset-4);
                                                        files.put(pname, path);
                                                        value = disposition.getProperty("filename");
                                                        value = value.substring(1,value.length()-1);
                                                        do {
                                                                mpline = in.readLine();
                                                        } while (mpline != null && mpline.indexOf(boundary) == -1);
                                                }
                                                parms.put(pname, value);
                                        }
                                }
                        }
                        catch ( IOException ioe )
                        {
                                sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
                        }
                }

                /**
                 * Find the byte positions where multipart boundaries start.
                **/
                public int[] getBoundaryPositions(byte[] b, byte[] boundary)
                {
                        int matchcount = 0;
                        int matchbyte = -1;
                        Vector matchbytes = new Vector();
                        for (int i=0; i<b.length; i++)
                        {
                                if (b[i] == boundary[matchcount])
                                {
                                        if (matchcount == 0)
                                                matchbyte = i;
                                        matchcount++;
                                        if (matchcount==boundary.length)
                                        {
                                                matchbytes.addElement(new Integer(matchbyte));
                                                matchcount = 0;
                                                matchbyte = -1;
                                        }
                                }
                                else
                                {
                                        i -= matchcount;
                                        matchcount = 0;
                                        matchbyte = -1;
                                }
                        }
                        int[] ret = new int[matchbytes.size()];
                        for (int i=0; i < ret.length; i++)
                        {
                                ret[i] = ((Integer)matchbytes.elementAt(i)).intValue();
                        }
                        return ret;
                }

                /**
                 * Retrieves the content of a sent file and saves it
                 * to a temporary file.
                 * The full path to the saved file is returned.
                **/
                private String saveTmpFile(byte[] b, int offset, int len)
                {
                        String path = "";
                        if (len > 0)
                        {
                                String tmpdir = System.getProperty("java.io.tmpdir");
                                try {
                                        File temp = File.createTempFile("NanoHTTPD", "", new File(tmpdir));
                                        OutputStream fstream = new FileOutputStream(temp);
                                        fstream.write(b, offset, len);
                                        fstream.close();
                                        path = temp.getAbsolutePath();
                                } catch (Exception e) { // Catch exception if any
                                        myErr.println("Error: " + e.getMessage());
                                }
                        }
                        return path;
                }


                /**
                 * It returns the offset separating multipart file headers
                 * from the file's data.
                **/
                private int stripMultipartHeaders(byte[] b, int offset)
                {
                        int i = 0;
                        for (i=offset; i<b.length; i++)
                        {
                                if (b[i] == '\r' && b[++i] == '\n' && b[++i] == '\r' && b[++i] == '\n')
                                        break;
                        }
                        return i+1;
                }

                /**
                 * Decodes the percent encoding scheme. <br/>
                 * For example: "an+example%20string" -> "an example string"
                 */
                private String decodePercent( String str ) throws InterruptedException
                {
                        try
                        {
                                StringBuffer sb = new StringBuffer();
                                for( int i=0; i<str.length(); i++ )
                                {
                                        char c = str.charAt( i );
                                        switch ( c )
                                        {
                                                case '+':
                                                        sb.append( ' ' );
                                                        break;
                                                case '%':
                                                        sb.append((char)Integer.parseInt( str.substring(i+1,i+3), 16 ));
                                                        i += 2;
                                                        break;
                                                default:
                                                        sb.append( c );
                                                        break;
                                        }
                                }
                                return sb.toString();
                        }
                        catch( Exception e )
                        {
                                sendError( HTTP_BADREQUEST, "BAD REQUEST: Bad percent-encoding." );
                                return null;
                        }
                }

                /**
                 * Decodes parameters in percent-encoded URI-format
                 * ( e.g. "name=Jack%20Daniels&pass=Single%20Malt" ) and
                 * adds them to given Properties. NOTE: this doesn't support multiple
                 * identical keys due to the simplicity of Properties -- if you need multiples,
                 * you might want to replace the Properties with a Hashtable of Vectors or such.
                 */
                private void decodeParms( String parms, Properties p )
                        throws InterruptedException
                {
                        if ( parms == null )
                                return;

                        StringTokenizer st = new StringTokenizer( parms, "&" );
                        while ( st.hasMoreTokens())
                        {
                                String e = st.nextToken();
                                int sep = e.indexOf( '=' );
                                if ( sep >= 0 )
                                        p.put( decodePercent( e.substring( 0, sep )).trim(),
                                                   decodePercent( e.substring( sep+1 )));
                        }
                }

                /**
                 * Returns an error message as a HTTP response and
                 * throws InterruptedException to stop further request processing.
                 */
                private void sendError( String status, String msg ) throws InterruptedException
                {
                        sendResponse( status, MIME_PLAINTEXT, null, new ByteArrayInputStream( msg.getBytes()));
                        throw new InterruptedException();
                }

                /**
                 * Sends given response to the socket.
                 */
                private void sendResponse( String status, String mime, Properties header, InputStream data )
                {
                        try
                        {
                                if ( status == null )
                                        throw new Error( "sendResponse(): Status can't be null." );

                                OutputStream out = mySocket.getOutputStream();
                                PrintWriter pw = new PrintWriter( out );
                                pw.print("HTTP/1.0 " + status + " \r\n");

                                if ( mime != null )
                                        pw.print("Content-Type: " + mime + "\r\n");

                                if ( header == null || header.getProperty( "Date" ) == null )
                                        pw.print( "Date: " + gmtFrmt.format( new Date()) + "\r\n");

                                if ( header != null )
                                {
                                        Enumeration e = header.keys();
                                        while ( e.hasMoreElements())
                                        {
                                                String key = (String)e.nextElement();
                                                String value = header.getProperty( key );
                                                pw.print( key + ": " + value + "\r\n");
                                        }
                                }

                                pw.print("\r\n");
                                pw.flush();

                                if ( data != null )
                                {
                                        int pending = data.available(); // This is to support partial sends, see serveFile()
                                        byte[] buff = new byte[theBufferSize];
                                        while (pending>0)
                                        {
                                                int read = data.read( buff, 0, ( (pending>theBufferSize) ?  theBufferSize : pending ));
                                                if (read <= 0)  break;
                                                out.write( buff, 0, read );
                                                pending -= read;
                                        }
                                }
                                out.flush();
                                out.close();
                                if ( data != null )
                                        data.close();
                        }
                        catch( IOException ioe )
                        {
                                // Couldn't write? No can do.
                                try { mySocket.close(); } catch( Throwable t ) {}
                        }
                }

                private Socket mySocket;
        }

        /**
         * URL-encodes everything between "/"-characters.
         * Encodes spaces as '%20' instead of '+'.
         */
        private String encodeUri( String uri )
        {
                String newUri = "";
                StringTokenizer st = new StringTokenizer( uri, "/ ", true );
                while ( st.hasMoreTokens())
                {
                        String tok = st.nextToken();
                        if ( tok.equals( "/" ))
                                newUri += "/";
                        else if ( tok.equals( " " ))
                                newUri += "%20";
                        else
                        {
                                newUri += URLEncoder.encode( tok );
                                // For Java 1.4 you'll want to use this instead:
                                // try { newUri += URLEncoder.encode( tok, "UTF-8" ); } catch ( java.io.UnsupportedEncodingException uee ) {}
                        }
                }
                return newUri;
        }

        private int myTcpPort;
        private final ServerSocket myServerSocket;
        private Thread myThread;
        private File myRootDir;

        // ==================================================
        // File server code
        // ==================================================

        /**
         * Serves file from homeDir and its' subdirectories (only).
         * Uses only URI, ignores all headers and HTTP parameters.
         */
        public Response serveFile( String uri, Properties header, File homeDir,
                                                           boolean allowDirectoryListing )
        {
                Response res = null;

                // Make sure we won't die of an exception later
                if ( !homeDir.isDirectory())
                        res = new Response( HTTP_INTERNALERROR, MIME_PLAINTEXT,
                                "INTERNAL ERRROR: serveFile(): given homeDir is not a directory." );

                if ( res == null )
                {
                        // Remove URL arguments
                        uri = uri.trim().replace( File.separatorChar, '/' );
                        if ( uri.indexOf( '?' ) >= 0 )
                                uri = uri.substring(0, uri.indexOf( '?' ));

                        // Prohibit getting out of current directory
                        if ( uri.startsWith( ".." ) || uri.endsWith( ".." ) || uri.indexOf( "../" ) >= 0 )
                                res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
                                        "FORBIDDEN: Won't serve ../ for security reasons." );
                }

                File f = new File( homeDir, uri );
                if ( res == null && !f.exists())
                        res = new Response( HTTP_NOTFOUND, MIME_PLAINTEXT,
                                "Error 404, file not found." );

                // List the directory, if necessary
                if ( res == null && f.isDirectory())
                {
                        // Browsers get confused without '/' after the
                        // directory, send a redirect.
                        if ( !uri.endsWith( "/" ))
                        {
                                uri += "/";
                                res = new Response( HTTP_REDIRECT, MIME_HTML,
                                        "<html><body>Redirected: <a href=\"" + uri + "\">" +
                                        uri + "</a></body></html>");
                                res.addHeader( "Location", uri );
                        }

                        if ( res == null )
                        {
                                // First try index.html and index.htm
                                if ( new File( f, "index.html" ).exists())
                                        f = new File( homeDir, uri + "/index.html" );
                                else if ( new File( f, "index.htm" ).exists())
                                        f = new File( homeDir, uri + "/index.htm" );
                                // No index file, list the directory if it is readable
                                else if ( allowDirectoryListing && f.canRead() )
                                {
                                        String[] files = f.list();
                                        String msg = "<html><body><h1>Directory " + uri + "</h1><br/>";

                                        if ( uri.length() > 1 )
                                        {
                                                String u = uri.substring( 0, uri.length()-1 );
                                                int slash = u.lastIndexOf( '/' );
                                                if ( slash >= 0 && slash  < u.length())
                                                        msg += "<b><a href=\"" + uri.substring(0, slash+1) + "\">..</a></b><br/>";
                                        }

                                        if (files!=null)
                                        {
                                                for ( int i=0; i<files.length; ++i )
                                                {
                                                        File curFile = new File( f, files[i] );
                                                        boolean dir = curFile.isDirectory();
                                                        if ( dir )
                                                        {
                                                                msg += "<b>";
                                                                files[i] += "/";
                                                        }

                                                        msg += "<a href=\"" + encodeUri( uri + files[i] ) + "\">" +
                                                                  files[i] + "</a>";

                                                        // Show file size
                                                        if ( curFile.isFile())
                                                        {
                                                                long len = curFile.length();
                                                                msg += " &nbsp;<font size=2>(";
                                                                if ( len < 1024 )
                                                                        msg += len + " bytes";
                                                                else if ( len < 1024 * 1024 )
                                                                        msg += len/1024 + "." + (len%1024/10%100) + " KB";
                                                                else
                                                                        msg += len/(1024*1024) + "." + len%(1024*1024)/10%100 + " MB";

                                                                msg += ")</font>";
                                                        }
                                                        msg += "<br/>";
                                                        if ( dir ) msg += "</b>";
                                                }
                                        }
                                        msg += "</body></html>";
                                        res = new Response( HTTP_OK, MIME_HTML, msg );
                                }
                                else
                                {
                                        res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
                                                "FORBIDDEN: No directory listing." );
                                }
                        }
                }

                try
                {
                        if ( res == null )
                        {
                                // Get MIME type from file name extension, if possible
                                String mime = null;
                                int dot = f.getCanonicalPath().lastIndexOf( '.' );
                                if ( dot >= 0 )
                                        mime = (String)theMimeTypes.get( f.getCanonicalPath().substring( dot + 1 ).toLowerCase());
                                if ( mime == null )
                                        mime = MIME_DEFAULT_BINARY;

                                // Calculate etag
                                String etag = Integer.toHexString((f.getAbsolutePath() + f.lastModified() + "" + f.length()).hashCode());

                                // Support (simple) skipping:
                                long startFrom = 0;
                                long endAt = -1;
                                String range = header.getProperty( "range" );
                                if ( range != null )
                                {
                                        if ( range.startsWith( "bytes=" ))
                                        {
                                                range = range.substring( "bytes=".length());
                                                int minus = range.indexOf( '-' );
                                                try {
                                                        if ( minus > 0 )
                                                        {
                                                                startFrom = Long.parseLong( range.substring( 0, minus ));
                                                                endAt = Long.parseLong( range.substring( minus+1 ));
                                                        }
                                                }
                                                catch ( NumberFormatException nfe ) {}
                                        }
                                }

                                // Change return code and add Content-Range header when skipping is requested
                                long fileLen = f.length();
                                if (range != null && startFrom >= 0)
                                {
                                        if ( startFrom >= fileLen)
                                        {
                                                res = new Response( HTTP_RANGE_NOT_SATISFIABLE, MIME_PLAINTEXT, "" );
                                                res.addHeader( "Content-Range", "bytes 0-0/" + fileLen);
                                                res.addHeader( "ETag", etag);
                                        }
                                        else
                                        {
                                                if ( endAt < 0 )
                                                        endAt = fileLen-1;
                                                long newLen = endAt - startFrom + 1;
                                                if ( newLen < 0 ) newLen = 0;

                                                final long dataLen = newLen;
                                                FileInputStream fis = new FileInputStream( f ) {
                                                        public int available() throws IOException { return (int)dataLen; }
                                                };
                                                fis.skip( startFrom );

                                                res = new Response( HTTP_PARTIALCONTENT, mime, fis );
                                                res.addHeader( "Content-Length", "" + dataLen);
                                                res.addHeader( "Content-Range", "bytes " + startFrom + "-" + endAt + "/" + fileLen);
                                                res.addHeader( "ETag", etag);
                                        }
                                }
                                else
                                {
                                        if (etag.equals(header.getProperty("if-none-match")))
                                                res = new Response( HTTP_NOTMODIFIED, mime, "");
                                        else
                                        {
                                                res = new Response( HTTP_OK, mime, new FileInputStream( f ));
                                                res.addHeader( "Content-Length", "" + fileLen);
                                                res.addHeader( "ETag", etag);
                                        }
                                }
                        }
                }
                catch( IOException ioe )
                {
                        res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Reading file failed." );
                }

                res.addHeader( "Accept-Ranges", "bytes"); // Announce that the file server accepts partial content requestes
                return res;
        }

        /**
         * Hashtable mapping (String)FILENAME_EXTENSION -> (String)MIME_TYPE
         */
        private static Hashtable theMimeTypes = new Hashtable();
        static
        {
                StringTokenizer st = new StringTokenizer(
                        "css            text/css "+
                        "htm            text/html "+
                        "html           text/html "+
                        "xml            text/xml "+
                        "txt            text/plain "+
                        "asc            text/plain "+
                        "gif            image/gif "+
                        "jpg            image/jpeg "+
                        "jpeg           image/jpeg "+
                        "png            image/png "+
                        "mp3            audio/mpeg "+
                        "m3u            audio/mpeg-url " +
                        "mp4            video/mp4 " +
                        "ogv            video/ogg " +
                        "flv            video/x-flv " +
                        "mov            video/quicktime " +
                        "swf            application/x-shockwave-flash " +
                        "js                     application/javascript "+
                        "pdf            application/pdf "+
                        "doc            application/msword "+
                        "ogg            application/x-ogg "+
                        "zip            application/octet-stream "+
                        "exe            application/octet-stream "+
                        "class          application/octet-stream " );
                while ( st.hasMoreTokens())
                        theMimeTypes.put( st.nextToken(), st.nextToken());
        }

        private static int theBufferSize = 16 * 1024;

        // Change these if you want to log to somewhere else than stdout
        protected static PrintStream myOut = System.out;
        protected static PrintStream myErr = System.err;

        /**
         * GMT date formatter
         */
        private static java.text.SimpleDateFormat gmtFrmt;
        static
        {
                gmtFrmt = new java.text.SimpleDateFormat( "E, d MMM yyyy HH:mm:ss 'GMT'", Locale.US);
                gmtFrmt.setTimeZone(TimeZone.getTimeZone("GMT"));
        }

        /**
         * The distribution licence
         */
        private static final String LICENCE =
                "Copyright (C) 2001,2005-2011 by Jarno Elonen <elonen@iki.fi>\n"+
                "and Copyright (C) 2010 by Konstantinos Togias <info@ktogias.gr>\n"+
                "\n"+
                "Redistribution and use in source and binary forms, with or without\n"+
                "modification, are permitted provided that the following conditions\n"+
                "are met:\n"+
                "\n"+
                "Redistributions of source code must retain the above copyright notice,\n"+
                "this list of conditions and the following disclaimer. Redistributions in\n"+
                "binary form must reproduce the above copyright notice, this list of\n"+
                "conditions and the following disclaimer in the documentation and/or other\n"+
                "materials provided with the distribution. The name of the author may not\n"+
                "be used to endorse or promote products derived from this software without\n"+
                "specific prior written permission. \n"+
                " \n"+
                "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"+
                "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\n"+
                "OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n"+
                "IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\n"+
                "INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\n"+
                "NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\n"+
                "DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\n"+
                "THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\n"+
                "(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n"+
                "OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.";
}

